Food allergies represent a clear threat to the general health and wellbeing of those affected which place increasing pressure on food producers and regulatory authorities. Current analytical techniques typically find ...Food allergies represent a clear threat to the general health and wellbeing of those affected which place increasing pressure on food producers and regulatory authorities. Current analytical techniques typically find difficulties distinguishing between closely related Prunus species which include almond (Prunus dulcis), an EU listed allergenic species. This study describes a proof of principle real-time PCR approach utilising DNA melt analyses that targets the internal transcribed spacer (ITS) sequence to differentiate between a panel of Prunus test species. The method was successfully applied to the characterisation of a commercial paprika sample suspected of having being adulterated with almond, referred to the UK Government Chemist in 2015 in its advisory capacity. Subject to further validation work, the method appears to specifically amplify Prunus species and is capable of discrimination based on the resultant melt profiles. The developed method provides analysts with a simple and broad molecular tool to identify common Prunus species for food authenticity and allergen testing purposes. Initial development work demonstrates a promising approach with the potential to improve discrimination between Prunus species not easily resolved by routine analytical methods.展开更多
Background: Pyrazinamide (PZA) is one of the most important drugs for tuberculosis (TB) treatment, however, its susceptibility is not routinely tested. High-resolution melting (HRM) curve analysis has been widely used...Background: Pyrazinamide (PZA) is one of the most important drugs for tuberculosis (TB) treatment, however, its susceptibility is not routinely tested. High-resolution melting (HRM) curve analysis has been widely used for many applications. In this study, HRM assay was developed and evaluated for the detection of PZA resistance in Mycobacterium tuberculosis clinical isolates. Methods: Ninety five M. tuberculosis clinical isolates with different susceptibility patterns to anti-TB drugs were used to evaluate this assay. Isolates were phenotypically (Bactec MGIT 960) and genotypically (HRM and pncA gene sequencing) analysed for PZA resistance. Results: Bactec MGIT 960 analysis revealed that 29 of the 95 M. tuberculosis isolates were PZA resistant. In comparison to the Bactec MGIT 960, HRM showed a sensitivity of 47.7% and specificity of 74.6%, and the overall agreement between the two methods was 68.4%. Based on DNA sequencing, a correlation of 0.67 (significant at p-value pncA mutations was observed. PZA resistance was strongly associated with multi-drug resistant (MDR)-TB as it was shown in 79.3% of the MDR isolates included in the study. Conclusion: HRM is simple and useful for screening clinical M. tuberculosis isolates for PZA resistance, however, further modifications to improve its performance are required.展开更多
Selective laser melting is an additive manufacturing method based on local melting of a metal powder bed by a high power laser beam. Fast laser scans are responsible for severe thermal gradients and high cooling rates...Selective laser melting is an additive manufacturing method based on local melting of a metal powder bed by a high power laser beam. Fast laser scans are responsible for severe thermal gradients and high cooling rates which produce complex hydrodynamic fluid flow. These phenomena affect crystal growth and orientation and are believed to be the cause of material spattering and microstructural defects, e.g. pores and incompletely melted particles. In this work, the microstructure and texture of 316L bars built along two different orientations and the effect of different distribution of defects on their mechanical response and failure mechanisms were investigated. Partially molten powder particles are believed to be responsible for the scattering in elongation to failure, reduced strength, and premature failure of vertical samples.展开更多
Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and poi...Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and point mutations, has been widely used in mutation induction and crop breeding. The present study aimed to develop a simple, high-throughput TILLING system for screening γ ray-induced mutations using high-resolution melting （HRM） analysis. Pooled rice （Oryza sativa） samples mixed at a 1：7 ratio of Indel mutant to wild-type DNA could be distinguished from the wild-type controls by HRM analysis. Thus, an HRM-TILLING system that analyzes pooled samples of four M2 plants is recommended for screening γ, ray-induced mutants in rice. For demonstration, a γ, ray-mutagenized M2 rice population （n=4560） was screened for mutations in two genes, OsLCT1 and SPDT, using this HRM-TILLING system. Mutations including one single nucleotide substitution （G→A） and one single nucleotide insertion （A） were identified in OsLCT1, and one tdnucleotide （TTC） deletion was identified in SPDT. These mutants can be used in rice breeding and genetic studies, and the findings are of importance for the application of γ, ray mutagenesis to the breeding of rice and other seed crops.展开更多
INTRODUCTION Atopic dermatitis （AD） is a common chronic inflammatory skin disorder that is characterized by dry skin and disturbed skin barrier functions. Mutations in the filaggrin （FLG） gene, the gene coding pro...INTRODUCTION Atopic dermatitis （AD） is a common chronic inflammatory skin disorder that is characterized by dry skin and disturbed skin barrier functions. Mutations in the filaggrin （FLG） gene, the gene coding profilaggrin/filaggrin, have a great impact on the epidermal barrier function and are an important predisposing factor for AD. However, in both Europeans and Asians,展开更多
Short tandem repeat(STR)profiling is one of the mostly used systems for forensic applications.In certain circumstances,STR profiling is time-consuming and costly,which potentially leads to delays in criminal investiga...Short tandem repeat(STR)profiling is one of the mostly used systems for forensic applications.In certain circumstances,STR profiling is time-consuming and costly,which potentially leads to delays in criminal investigations.LGC(Laboratory of the Government Chemist,UK)Forensics has developed a robust STR profiling platform called the ParaDNAVR Intelligence Test System which can provide early tactical intelligence and aid investigators in making informed decisions on sample prioritization for detection.Here,we validated the ParaDNA^(■) intelligence test for its application in forensic cases using a range of mock evidence items following guidelines set by the Scientific Working Group on DNA Analysis Methods(SWGDAM).Specifically,we tested the sensitivity and accuracy of the ParaDNA intelligence test,as well as the success rates for detecting mock samples and for use in case scenarios.Our findings demonstrate that the ParaDNA intelligence test generates useful DNA profiles,especially for samples such as blood,saliva,and semen that contain ample DNA,indicating the benefits of including ParaDNA as a prior step in forensic STR profiling pipelines.展开更多
文摘Food allergies represent a clear threat to the general health and wellbeing of those affected which place increasing pressure on food producers and regulatory authorities. Current analytical techniques typically find difficulties distinguishing between closely related Prunus species which include almond (Prunus dulcis), an EU listed allergenic species. This study describes a proof of principle real-time PCR approach utilising DNA melt analyses that targets the internal transcribed spacer (ITS) sequence to differentiate between a panel of Prunus test species. The method was successfully applied to the characterisation of a commercial paprika sample suspected of having being adulterated with almond, referred to the UK Government Chemist in 2015 in its advisory capacity. Subject to further validation work, the method appears to specifically amplify Prunus species and is capable of discrimination based on the resultant melt profiles. The developed method provides analysts with a simple and broad molecular tool to identify common Prunus species for food authenticity and allergen testing purposes. Initial development work demonstrates a promising approach with the potential to improve discrimination between Prunus species not easily resolved by routine analytical methods.
文摘Background: Pyrazinamide (PZA) is one of the most important drugs for tuberculosis (TB) treatment, however, its susceptibility is not routinely tested. High-resolution melting (HRM) curve analysis has been widely used for many applications. In this study, HRM assay was developed and evaluated for the detection of PZA resistance in Mycobacterium tuberculosis clinical isolates. Methods: Ninety five M. tuberculosis clinical isolates with different susceptibility patterns to anti-TB drugs were used to evaluate this assay. Isolates were phenotypically (Bactec MGIT 960) and genotypically (HRM and pncA gene sequencing) analysed for PZA resistance. Results: Bactec MGIT 960 analysis revealed that 29 of the 95 M. tuberculosis isolates were PZA resistant. In comparison to the Bactec MGIT 960, HRM showed a sensitivity of 47.7% and specificity of 74.6%, and the overall agreement between the two methods was 68.4%. Based on DNA sequencing, a correlation of 0.67 (significant at p-value pncA mutations was observed. PZA resistance was strongly associated with multi-drug resistant (MDR)-TB as it was shown in 79.3% of the MDR isolates included in the study. Conclusion: HRM is simple and useful for screening clinical M. tuberculosis isolates for PZA resistance, however, further modifications to improve its performance are required.
文摘Selective laser melting is an additive manufacturing method based on local melting of a metal powder bed by a high power laser beam. Fast laser scans are responsible for severe thermal gradients and high cooling rates which produce complex hydrodynamic fluid flow. These phenomena affect crystal growth and orientation and are believed to be the cause of material spattering and microstructural defects, e.g. pores and incompletely melted particles. In this work, the microstructure and texture of 316L bars built along two different orientations and the effect of different distribution of defects on their mechanical response and failure mechanisms were investigated. Partially molten powder particles are believed to be responsible for the scattering in elongation to failure, reduced strength, and premature failure of vertical samples.
基金Project supported by the National Key Research and Development Program of China(No.2016YFD0102103)
文摘Targeting Induced Local Lesions IN Genomes （TILLING） is a reverse genetics strategy for the high-throughput screening of induced mutations.γ, radiation, which often induces both insertion/deletion （Indel） and point mutations, has been widely used in mutation induction and crop breeding. The present study aimed to develop a simple, high-throughput TILLING system for screening γ ray-induced mutations using high-resolution melting （HRM） analysis. Pooled rice （Oryza sativa） samples mixed at a 1：7 ratio of Indel mutant to wild-type DNA could be distinguished from the wild-type controls by HRM analysis. Thus, an HRM-TILLING system that analyzes pooled samples of four M2 plants is recommended for screening γ, ray-induced mutants in rice. For demonstration, a γ, ray-mutagenized M2 rice population （n=4560） was screened for mutations in two genes, OsLCT1 and SPDT, using this HRM-TILLING system. Mutations including one single nucleotide substitution （G→A） and one single nucleotide insertion （A） were identified in OsLCT1, and one tdnucleotide （TTC） deletion was identified in SPDT. These mutants can be used in rice breeding and genetic studies, and the findings are of importance for the application of γ, ray mutagenesis to the breeding of rice and other seed crops.
文摘INTRODUCTION Atopic dermatitis （AD） is a common chronic inflammatory skin disorder that is characterized by dry skin and disturbed skin barrier functions. Mutations in the filaggrin （FLG） gene, the gene coding profilaggrin/filaggrin, have a great impact on the epidermal barrier function and are an important predisposing factor for AD. However, in both Europeans and Asians,
基金This study was supported by grants from National Key R&D Program of China[grant number 2016YFC0800703]the National Natural Science Foundation of China[grant number 81601651 and 81625013]+2 种基金the Ministry of Finance of China[grant number GY2016D1,GY2018G-9,KF1813]the Shanghai Science and Technology Innovation Fund[grant number 16DZ1205500,16DZ2290900,17DZ2273200]the funders had no role in study design,data analysis,decision to publish,or preparation of the manuscript.
文摘Short tandem repeat(STR)profiling is one of the mostly used systems for forensic applications.In certain circumstances,STR profiling is time-consuming and costly,which potentially leads to delays in criminal investigations.LGC(Laboratory of the Government Chemist,UK)Forensics has developed a robust STR profiling platform called the ParaDNAVR Intelligence Test System which can provide early tactical intelligence and aid investigators in making informed decisions on sample prioritization for detection.Here,we validated the ParaDNA^(■) intelligence test for its application in forensic cases using a range of mock evidence items following guidelines set by the Scientific Working Group on DNA Analysis Methods(SWGDAM).Specifically,we tested the sensitivity and accuracy of the ParaDNA intelligence test,as well as the success rates for detecting mock samples and for use in case scenarios.Our findings demonstrate that the ParaDNA intelligence test generates useful DNA profiles,especially for samples such as blood,saliva,and semen that contain ample DNA,indicating the benefits of including ParaDNA as a prior step in forensic STR profiling pipelines.
